Histopathological study of intraductal papillary mucinous tumor of the pancreas: special reference to the roles of Survivin and p53 in tumorigenesis of IPMT

Repurposing metformin, simvastatin and digoxin as a combination for targeted therapy for pancreatic ductal adenocarcinoma

Patients with pancreatic adenocarcinoma (PDAC) have a 5-year survival rate of 8%, the lowest of any cancer in the United States. Traditional chemotherapeutic regimens, such as gemcitabine- and fluorouracil-based regimens, often only prolong survival by months. Effective precision targeted therapy is therefore urgently needed to substantially improve survival. In an effort to expedite approval and delivery of targeted therapy to patients, we utilized a platform to develop a novel combination of FDA approved drugs that would target pancreaticoduodenal homeobox1 (PDX1) and baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5) utilizing super-promoters of the target genes to interrogate an FDA approved drug library. We identified and selected metformin, simvastatin and digoxin (C3) as a novel combination of FDA approved drugs, which were shown to effectively target PDX1 and BIRC5 in human PDAC tumors in mice with no toxicity.

BIRC5 is a target for molecular imaging and detection of human pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a major cause of cancer mortality with a dismal overall survival rate and an urgent need for detection of minute tumors. Current diagnostic modalities have high sensitivity and specificity for larger tumors, but not for minute PDAC. In this study, we test the feasibility of a precision diagnostic platform for detecting and localizing minute human PDAC in mice. This platform includes: 1) defining BIRC5 as an early PDAC-upregulated gene and utilizing an enhanced BIRC5 super-promoter to drive expression of dual Gaussia luciferase (GLuc) and sr39 thymidine kinase (sr39TK) reporter genes exponentially and specifically in PDAC; 2) utilizing a genetically-engineered AAV₂^RGD to ensure targeted delivery of GLuc and sr39TK specifically to PDAC; 3) using serologic GLuc and sr39TK microPET/CT imaging to detect and localize minute human PDAC in mice. The study demonstrates feasibility of a precision diagnostic platform using an integrated technology through a multiple-stage amplification strategy of dual reporter genes to enhance the specificity and sensitivity of detection and localization of minute PDAC tumors and currently undetectable disease.

The role of apoptosis in blepharoptosis

PURPOSE

The purpose of this study is to evaluate the role of apoptosis in the pathogenesis of blepharoptosis.

PATIENTS AND METHODS

Forty-five eyelids of 43 consecutive patients (16 female, 27 males) that underwent levator resection surgery for ptosis correction were included in the study. Twenty-six of the eyelids had congenital myogenic ptosis and 19 had aponeurotic ptosis. Levator palpebrae superioris function and height of the vertical palpebral fissure were measured in all patients. After levator resection surgery, the distal part of the levator aponeurosis was fixed and sent for evaluation. Apoptotic cells were detected using Apop Tag Plus Peroxidase In Situ Apoptosis Detection Kit.

RESULTS

The mean levator palpebrae superioris function was 8.4 mm (range 5-10 mm) in congenital ptosis group and 12.1 mm (range 10-17 mm) in the aponeurotic ptosis group. The mean height of the vertical palpebral fissure in patients with congenital ptosis and aponeurotic ptosis were 6.5 mm (range 5-9 mm) and 6.1 mm (3-9 mm), respectively. The mean apoptotic index of congenital ptosis and aponeurotic ptosis were 27.3 (16-39) and 29.8 (18-41), respectively. There was no statistically significant difference between congenital and aponeurotic ptosis groups in a mean apoptotic index (P<0.05). Apoptotic index was not correlated with age, levator palpebrae superioris function, palpebral fissure height, and lid crease height in two groups.

CONCLUSION

We found no statistically significant difference between two subtypes of blepharoptosis regarding apoptosis. According to this study, apoptosis seems to have no significant role in the development of aponeurotic blepharoptosis.

Genetic markers of malignant transformation in intraductal papillary mucinous neoplasm of the pancreas: a meta-analysis

OBJECTIVES

The objective of this study was to determine the relationship between specific genetic alterations and malignant transformation in intraductal papillary mucinous neoplasm (IPMN) of the pancreas.

METHODS

Quantitative meta-analysis was conducted of studies through October 2010 that adhered to the 1996 World Health Organization guidelines for distinguishing adenoma and borderline IPMN versus carcinoma in surgically resected specimens using a random-effects model. We developed a 6-point scoring system to assess study quality.

RESULTS

Thirty-nine studies (1235 IPMN samples) satisfied the inclusion criteria, and we conducted pooled analysis of 8 genetic markers: MUC1, MUC2, MUC5AC, kRas, p53, hTERT (human telomerase reverse transcriptase), cyclooxygenase 2, and Shh (Sonic hedgehog). Markers having the strongest association with malignant IPMN were hTERT (odds ratio [OR], 11.4; 95% confidence interval [CI], 3.5-36.7) and Shh (OR, 6.9; 95% CI, 2.4-20.2), whereas MUC5AC (OR, 1.0; 95% CI, 0.1-13.9) and kRas (OR, 2.0; 95% CI, 1.0-4.3) showed weak association with IPMN histologic progression.

CONCLUSIONS

Expression of hTERT is strongly associated with malignant transformation in IPMN, consistent with up-regulation of hTERT as a key step in progression of IPMN to cancer. Expression of kRas and MUC5AC is common but not strongly associated with IPMN histologic progression. The quality criteria used here may guide future reporting of genetic markers related to malignant transformation of IPMN.

Nuclear survivin expression is a positive prognostic factor in taxane-platinum-treated ovarian cancer patients

Background

Survivin is an inhibitor of apoptosis and a regulator of mitotic progression. TP53 protein is a negative transcriptional regulator of survivin. The aim of our study was to evaluate the clinical significance of survivin expression in advanced stages ovarian cancer with respect to the TP53 status.

Methods

Survivin and TP53 expression was evaluated immunohistochemically in 435 archival samples of ovarian carcinomas (244 patients were treated with platinum/cyclophosphamide-PC/PAC; 191-with taxane-platinum (TP) agents). Univariate and multivariate statistical analyses were performed in patients groups divided according to the administered chemotherapeutic regimen, and in subgroups with and without TP53 accumulation (TP53+ and TP53-, respectively).

Results

Nuclear and cytoplasmic survivin expression was observed in 92% and 74% of the carcinomas, respectively. In patients treated with TP, high nuclear survivin expression decreased the risk of disease recurrence and death, and increased the probability of high platinum sensitivity (p < 0.01), but only in the TP53(+) group, and not in the TP53(-) group.

Conclusions

It appears that TP53 status determines the clinical importance of nuclear survivin expression in taxane-platinum treated ovarian cancer patients.

Survivin and pancreatic cancer

Pancreatic cancer is estimated to be the fourth most common cancer in men and fifth in women in the world and has poor prognosis. In recent years, more and more effort has been put on the relationship between pancreatic cancer and apoptosis. As a newly discovered inhibitor of apoptosis, survivin has drawn more attention. Strong evidence has shown that survivin is expressed in pancreatic cancer cells on frozen sections. Survivin increases in the development of pancreatic ductal adenocarcinoma and its expression can be a marker in evaluating the prognosis of pancreatic cancer patients. Survivin itself may be a new target in the treatment of pancreatic cancer and a survivin DNA vaccine could generate specific antitumor effects in pancreatic carcinoma models.

High-throughput mutation profiling in intraductal papillary mucinous neoplasm (IPMN)

BACKGROUND

Specific mutations leading to the development of various histological grades of intraductal papillary mucinous neoplasm (IPMN) have been partially characterized.

METHODS

Analysis of 323 oncogenic mutations in 22 tumor-related genes was conducted, using a chip-based matrix-assisted laser desorption time-of-flight mass spectrometer of DNA extracted from microdissected cells of low-grade (n = 14), borderline (n = 6), and invasive IPMN (n = 7). Additional assays were performed on the DNA extracted from dyplastic cells found in the background of the adenocarcinoma.

RESULTS

We identified 9 K-ras mutations (low grade, 2/14; borderline, 1/6; invasive, 6/7), 3 p53 mutations (low grade, 1/14; invasive 2/7), and 2 PIK3CA mutations (low grade, 1/14; invasive, 1/7). K-ras, p53, and PIK3CA mutations present in the invasive cancer were absent in the adjacent precursor cells in 50% of the cases. In one patient, K-ras mutation was present in the precursor lesion and absent in the adjacent invasive lesion.

CONCLUSIONS

Of the 22 screened tumor-related genes, only K-ras, p53, and PIK3CA mutations were found in IPMN. K-ras mutations are more prevalent in invasive than premalignant IPMN. The variable coexistence of mutations in the invasive cancer and in the adjacent precursor cells may point to the heterogeneous nature of this tumor.

Different patterns of p16INK4A and p53 protein expressions in intraductal papillary-mucinous neoplasms and pancreatic intraepithelial neoplasia

OBJECTIVES

To examine aberrations and differences of cell cycle regulatory proteins between intraductal papillary-mucinous neoplasms (IPMNs) and pancreatic intraepithelial neoplasias (PanINs).

METHODS

In total, 47 IPMN lesions and 42 PanIN lesions were obtained from 26 patients with IPMN and 16 patients who underwent pancreatic surgery for invasive pancreatic ductal cancer or other diseases. They were subjected to conventional hematoxylin-eosin staining and immunostaining for p16INK4A and p53. The percentages of immunohistochemical positivity or negativity were compared between IPMN and PanIN, in accordance with the same histological grade of atypia. The Ki-67 labeling index was also counted in each lesion.

RESULTS

Either the loss of p16INK4A expression or the overexpression of p53 was much more frequently observed among PanIN-3 than among carcinoma in situ in IPMN (P = 0.046 and 0.008, respectively). The Ki-67 labeling index was correlated with the histological grades of both PanINs and IPMNs (P = 0.0001 and P = 0.0001, respectively).

CONCLUSIONS

There are different immunohistochemical expression patterns of p16INK4A and p53 between IPMNs and PanINs. These may substantiate their different genetic progressions to invasive carcinoma.

Survivin expression in pancreatic intraepithelial neoplasia (PanIN): steady increase along the developmental stages of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive gastrointestinal cancers and is thought to arise from noninvasive precursors-pancreatic intraepithelial neoplasia (PanIN). Aberrantly prolonged cell survival due to apoptosis suppression is likely to contribute to carcinogenesis and carcinoma progression where the inhibitor of apoptosis proteins (IAPs) may play an important role. IAPs specifically inhibit caspases 3, 7, and 9 and prevent apoptosis. Survivin is a unique member of the IAPs family that is expressed in most human cancers including PDA but is not expressed in most normal adult tissues. To measure survivin transcript levels in normal pancreatic ducts, PanINs, and PDA, we used laser capture microdissection and real-time polymerase chain reaction. Survivin protein expression in normal pancreatic ducts, PanINs, PDA, and its metastases to lymph nodes were evaluated by immunohistochemistry. In microdissected tissues, we found a steady and close to exponential increase in survivin transcript levels from low-grade lesions (PanINs-1) to high-grade lesions (PanINs-2 and 3) and further to PDA. This observation was strictly mirrored by survivin protein expression. In addition, survivin was localized to the nucleus in high-grade lesions (starting at PanIN-2 stage), PDA, and nodal metastases, suggesting that nuclear translocation of survivin may be an early event in transformation to malignancy.

Autoimmune response to anti-apoptotic protein survivin and its association with antibodies to p53 and c-myc in cancer detection

Survivin, an inhibitor of apoptotic protein, is over-expressed in many cancers but not in normal differentiated adult tissues. Recently, antibodies to survivin have been demonstrated in patients with lung and colorectal cancer. Whether antibodies to survivin can be used as a marker for the diagnosis of cancer, and how antibody to survivin is related to antibodies against tumor suppressor protein p53 and oncoprotein c-myc remains to be evaluated. In the present study, the full-length recombinant proteins survivin, p53 and c-myc, were expressed and used as antigens in enzyme-linked immunosorbent assay (ELISA) and Western blot for the detection of antibodies to these three proteins. Sera from 1137 patients with 11 different types of cancer were analyzed. Antibodies to survivin were detected in 8.4% (96/1137), with a significant difference from the control groups consisting of normal individuals and autoimmune disease patients (p<0.05). Of 1137 cancer sera, 546 were also tested for the presence of antibodies to p53 and c-myc. Frequencies of antibodies to p53 and c-myc were 11.5 and 12.3%, respectively. Although antibodies to either one of three antigens do not reach levels of sensitivity, which could become routinely useful in diagnosis, it appears that there are different patterns of antibody frequency in individual cancer type. The results also indicated that when the presence of antibody to any one of these three antigens was considered, the cumulative frequency was increased to 27.3% (149/546) for the total group of cancer patients. It became apparent from our data that the combination of antibodies might acquire higher sensitivity.

Survivin expression and its clinical significance in pancreatic cancer

BACKGROUND

Survivin, an inhibitor of apoptosis is expressed in several human cancers. Its expression is known to be associated with poor clinical outcome, but not widely studied in pancreatic cancer. We performed this study to determine the survivin expression in pancreatic cancer and its clinical significance as a prognostic factor.

METHODS

We performed immunohistochemical staining for survivin, p53, and Bax in formalin-fixed, paraffin-embedded block from forty-nine pancreatic tissues. To determine the association with clinical course, we reviewed the patients' clinical record.

RESULTS

Of the 49 cases of pancreatic cancer, 46 cases (93.9%) were positive for survivin expression. There was no significant association between survivin expression and p53 or bax. For clinicopathological parameters, perineural invasion was more common in survivin positive and venous invasion was more common in survivin negative (p = 0.041 and 0.040, respectively). Responsiveness to chemotherapy appeared to be slightly better in patients with low survivin expression.

CONCLUSION

Survivin expression may be associated with venous or perineural invasion, indicating metastatic route, and seems to have a potential as a predictive marker for chemotherapy. Further study of large scale is required to determine the clinical significance of survivin expression in pancreatic cancer.

DNAzyme-mediated cleavage of survivin mRNA and inhibition of the growth of PANC-1 cells

BACKGROUND AND AIM

Survivin has functions in both the regulation of cell division and the inhibition of apoptosis, and it is expressed in most human tumors but not in normal adult tissues. It is a potential target for cancer gene therapy. In the present study, we designed a DNAzyme targeting human survivin mRNA and tried to determine its effect on human pancreatic carcinoma cell line PANC-1.

METHODS

We designed and synthesized a '10-23' antisurvivin mRNA DNAzyme, testified its cleavage activity by cell-free test, then delivered it into the PANC-1 cell line through liposome, and detected its effect on survivin mRNA expression by reverse transcription polymerase chain reaction, Western blot methods, evaluated its influence on the growth of PANC-1 cells by apoptosis detection, growth curve, and flow cytometry.

RESULTS

Our results showed that the DNAzyme digested mRNA substrates of survivin efficiently in a dosage- and time-dependent manner, markedly increased apoptosis and inhibited the growth of human pancreatic carcinoma cell line PANC-1, compared with the disabled DNAzyme and untreated controls.

CONCLUSIONS

Our results showed that the designed DNAzyme against survivin mRNA is a good candidate for cancer gene therapy of human pancreatic carcinoma.

Biological similarities and differences between pancreatic intraepithelial neoplasias and intraductal papillary mucinous neoplasms

BACKGROUND

Ever since the classification of pancreatic intraepithelial neoplasia (PanIN) was published, studies on the precursor lesions of pancreatic cancer have been advancing along a new directions, using standardized terminology. There are few studies that have examined the biological differences between PanIN and intraductal papillary mucinous neoplasm (IPMN) in detail.

AIMS

PanIN and IPMN, which are similar in morphology, were compared using various indicators, with the aim of identifying the similarities and differences between the two.

METHODOLOGY

A total of 46 PanINs and 37 ducts with IPMN were identified in 19 patients with invasive ductal carcinoma and 18 patients with IPMN. These PanINs and IPMNs were examined immunohistologically with respect to the expression patterns of HER2/neu, DPC4/Smad4, Akt/PKB, p53, cyclin A, Ki67, MUC1, and MUC2.

RESULTS

Significant differences in the expression of MUC1 and MUC2 were observed between IPMNadenoma and PanIN-2 and between CIS and PanIN-3 (MUC1: p = 0.001 and p = 0.005, respectively; MUC2: p = 0.002 and p < 0.001, respectively). A significant difference in the p53 expression level was also observed between CIS and PanIN-3 (p = 0.015).

CONCLUSIONS

In both IPMN and PanIN, the grade of atypism increased with increasing expression of HER2/neu, DPC4/Smad4, and Akt/PKB, along with progression in the process of multistage carcinogenesis. Although the expression levels of these factors reflected the grade of atypism, they did not reflect any differences in the grade of biological malignancy between IPMN and PanIN. On the other hand, MUC1 and MUC2 may serve as indicators of the direction of differentiation, i.e., either progression to IDAC or IPMN. Positivity for MUC1 was believed to suggest differentiation into IDAC, and positivity for MUC2 appeared to be indicative of differentiation into IPMN. Such indication of the direction of differentiation seemed to appear in PanIN1-2, even before abnormalities of HER2/neu, Akt/PKB, DPC4/Smad4, p53, and cyclin A expression began to be detected.

Initial apoptosis is followed by increased proliferation of apoptosis-resistant endothelial cells

We have demonstrated that VEGF receptor blockade in combination with chronic hypoxia causes in rats severe angioproliferative pulmonary hypertension (SAPH) associated with arterial occlusion by proliferating endothelial cells, and we postulate that the established, lumen-occluding lesions are the result of the emergence of apoptosis-resistant proliferating cells. To study the dependence of exuberant endothelial cell proliferation on initial apoptosis, we adapted the CELLMAX artificial capillary system to analyze the effects of a VEGF receptor antagonist (SU5416) on human pulmonary microvascular endothelial cells under pulsatile shear stress. Immunohistochemical staining for caspase-3 and PCNA and flow cytometry for Annexin-V and BrdU supported our concept, since SU5416 caused initial apoptosis (35.8% at 24 h after the SU5416 addition and 4.8% in control cells) whereas the surviving cells became hyperproliferative (PCNA positive). Flow cytometry showed that apoptosis inhibition prevented the proliferation following the initial apoptosis. These lumen-filling endothelial cells were apoptosis resistant, grew without serum, and were phenotypically altered in that they express the tumor marker survivin. Hyperproliferative apoptosis-resistant cells were also generated by adding apoptosed cells instead of the VEGF receptor blocker to the CELLMAX system. In conclusion, endothelial cell death resulted in the selection of an apoptosis-resistant, proliferating phenotypically altered endothelial cell phenotype.

Mucin expression profile is related to biological and clinical characteristics of intraductal papillary-mucinous tumors of the pancreas

OBJECTIVES

Biologic and clinical characteristics of intraductal papillary-mucinous tumors of the pancreas (IPMTs) were studied in reference to immunohistochemical mucin (MUC1, MUC2, and MUC5AC) expression.

METHODS

Histologic grade, immunohistochemical ki-67 and p53 expression, and findings in imaging tests of 21 IPMTs (9 carcinomas, 6 borderline tumors, and 6 adenomas) were examined according to the mucin expression profile.

RESULTS

IPMTs were divided into groups: M1 group (MUC1+, n = 4), M2 group (MUC2 + MUC1-, n = 12), and M5 group (MUC5AC + MUC1-MUC2-, n = 5). The M2 group was subdivided into M2s (strongly positive) and M2w (weakly positive) groups. The rates of carcinoma in the M1, M2s, M2w, and M5 groups were 100%, 40%, 0%, and 0%, respectively. The Ki-67 labeling indexes were significantly higher in the M1 and M2s groups. p53 staining was positive in 50% and 40% of the IPMTs in the M1 and M2s groups, respectively, but in none of the IPMT in the M2w and M5 groups. Morphologic changes in imaging tests during the observation periods were most remarkable in the M1 group.

CONCLUSIONS

Our results suggest that MUC1 is related to malignant character but MUC5AC alone is related to benign character in IPMTs and that malignant potential of IPMTs expressing MUC2 depends on the degree of MUC2 expression.

Immunohistochemical analysis of molecular biological factors in intraductal papillary-mucinous tumors and mucinous cystic tumors of the pancreas

BACKGROUND

To investigate the malignancy and differentiation of intraductal papillary-mucinous tumors (IPMTs) and mucinous cystic tumors (MCTs) of the pancreas, clinicopathologic characteristics and immunohistochemical features were analyzed.

METHODS

The clinicopathologic characteristics and immunohistochemical features of 24 patients with IPMT and 8 with MCT who underwent pancreatic resections at our hospital were examined. Immunohistochemical features analyzed included expression of p53 protein, proliferating cell nuclear antigen, integrins, interleukin-1 receptor type I, and hormone-associated receptors, and the factors correlated with malignancy were identified by multiple logistic regression.

RESULTS

Among the IPMTs, there were 16 intraductal papillary adenomas, 5 intraductal papillary adenocarcinomas, and 3 moderate dysplasias. Among the MCTs, there were 6 mucinous cyst adenomas and 2 mucinous cyst adenocarcinomas. Multivariate analysis revealed that of the clinicopathologic characteristics, only the presence of mural nodules (odds ratio (OR) 7.12, P = 0.044) was independently correlated with the malignancy of IPMTs, and that of the immunohistochemical features, only alpha integrin subunit expression was independently correlated with malignancy of pancreatic mucinous tumors (OR 15.6, P = 0.036), especially IPMTs (OR 35.7, P = 0.012).

CONCLUSION

These results indicate that alpha-containing integrin expression can be a significant marker of malignancy in pancreatic mucinous tumors.

Expression of Survivin in pancreatic cancer and its correlation to expression of Bcl-2

AIM: To investigate the expression of Survivin in pancreatic cancer and its correlation to the expression of Bcl-2.

METHODS: Survivin and Bcl-2 expressions were examined by immunohistochemistry in 42 tissue samples from pancreatic cancer and 10 from normal pancrease.

RESULTS: No survivin expression was detected in the tissue samples from normal pancrease, while it was detected in 34 of 42 tissue samples from pancreatic cancer (81.95%). There was a correlation between survivin expression and differentiation and stages of pancreatic cancer. Survivin positive cases were strongly correlated to Bcl-2 expression (28/30 vs 6/12, P < 0.05).

CONCLUSION: Overexpression of survivin plays an important role in the development and progression of pancreatic cancer, and correlates to the expression of Bcl-2. Survivin expression can be used as a prognostic factor.